Zip fastener

ABSTRACT

A zip slider comprises: a body ( 200 ) having two channels through which opposing rows of zip teeth may be respectively fed into a single channel in which the zip teeth are forced into interdigitation; upper and lower jaw members ( 114, 140 ) mounted on the body ( 200 ) and defining a slot between them; a biasing member ( 180 ), pivotally mounted on the body ( 200 ), and being pivotable in a first direction between a rest position and a deflected position, wherein pivoting of the biasing member ( 180 ) out of the rest position permits insertion of a loop of a pull tab into the jaws ( 114, 140 ) and, in the rest position, the biasing member ( 180 ) prohibits removal of the pull tab from the jaws ( 114, 140 ).

BACKGROUND TO THE INVENTION

1. Field of the Invention

The present invention relates to a zip fastener, and more particularly to a zip slider.

Typically, a zip comprises two rows of mutually-opposing teeth. The fastening action of the zip is achieved by interdigitating the teeth of opposing rows with each other, thereby causing the rows to knit together along their lengths. This interdigitation is achieved by means of a zip slider. Motion of the zip slider is guided along the length of the teeth by virtue of its engagement with the teeth. Simultaneously, the zip slider comprises a pair of channels through which opposing teeth pass when the slider is moved along the length of the zip; and it is by means of these channels that the teeth are forced into mutual engagement (or, in the case of un-zipping by reversing the motion of the slider relative to the teeth, disengagement) as the slider moves. Motion of the zip slider is most usually powered manually. To facilitate this, a pull tab is typically pivotally mounted on the slider to enable easy gripping of the slider.

2. Description of Related Art

The present invention relates to a zip slider which comprises a detachable pull tab. Detachable pull tabs, that is to say pull tabs which may be applied to the zip slider after manufacture of the zip (and, where required, a garment in which the zip has been incorporated) are known per se. For example, EP 1987730, JP2131704 and GB 2165583 both show zip sliders with detachable pull tabs.

SUMMARY OF THE INVENTION

The present invention provides alternative forms of zip slider.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a zip slider according to an embodiment of the present invention;

FIG. 2 is a cutaway perspective view of the slider shown in FIG. 1;

FIG. 3 is a plan view of the slider shown in FIGS. 1 and 2;

FIG. 4 is a section on A-A in FIG. 3;

FIG. 5 is a cutaway perspective view of a zip slider according to an embodiment of the present invention with a pull tab attached;

FIG. 6 is a side view of the slider shown in FIG. 5;

FIG. 7 is a perspective side view of a zip slider body according to an embodiment of the present invention;

FIG. 8 is a perspective side view of the zip slider body of FIG. 7 from the opposite side;

FIG. 9 is an exploded perspective view of the zip slider of FIGS. 7 and 8 in conjunction with additional components to provide locking and retention of a pull tab;

FIG. 10 is a section through the slider of FIG. 9;

FIG. 11 is an assembled perspective view of a modified version of the slider of FIGS. 7 to 10;

FIG. 12 is a section through shown the zip slider of FIG. 11; and

FIG. 13 is a perspective side view of a further embodiment of zip slider according to the present invention which does not incorporate any locking mechanism.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIGS. 1 to 4, a slider comprises a body 10 having a base part 12 made of two mutually opposing plates 14, 16 which, in common with a standard zip slider, are formed to create two angled entry channels 18 into which the teeth of the two opposing parts of an unfastened zip (not shown) are fed. The entry channels feed into a single mating channel 20 and, as the slider is moved along the zip the forces applied to the zip teeth by the side walls 22 of the plates 14 urge the teeth to interdigitate thereby to knit together and cause the zip to fasten when the zip slider is moved relative to the zip in the direction of arrow F in FIG. 4 or, when moved in the opposite direction, to disengage and cause the zip to unfasten. Referring additionally to FIGS. 5 and 6, movement of the slider relative to the zip teeth is actuated by means of a pull tab 100.

To provide for connection of the pull tab 100 to the slider body 10, the slider has an upper body 40 (sometimes referred to as a ‘bridge’) mounted on the base 12 of the slider which, in conjunction with the upper plate 14 of the base 12 forms a pair of jaws 50 into which a window section 110 of the pull tab 30 may be inserted and by means of which the pull tab 100 may be retained on the slider 10. In the design of the present embodiment enables the upper body 40 to be cast solidly with the other elements of the slider body, unlike existing locking sliders which are are formed from several pieces. The upper body 40 retains a locking member 60 which comprises a prong 62 that projects through an aperture 70 in the upper plate 14 and into the mating channel 20. In this way the prong 62 thereby is able to bear against the knitted teeth of the zip in the mating channel to provide a force to retain the slider in position relative to the zip. The locking member 60 is movable relative to the upper body 40 to provide for projection of the prong 62 into the mating channel 20 and retraction of the pawl out of the mating channel 20. In the present embodiment the locking member 60 is mounted on the upper body for pivoting motion relative to the upper body 40 about its point of contact 64 and by virtue of a clearance 66.

The prong is biased into a position where it projects into the mating channel 20 (and thereby into a position of engagement with the knitted zip teeth) by means of a biasing spring, which in the present embodiment is provided by a wire loop spring 80 having two limbs 82 which extend from a loop 84 at its base, which sits in a slot 67 formed in the locking member 60. The loop spring 80 further has two spigots 86 which project outwardly from the upper ends of the limbs 82 and which extend into apertures 88 in the upper body 40 thereby to locate the spring in the upper body 40 in a manner permitting pivotal motion of the loop 84 at its lower extent relative to the upper body 40. The spring is formed in such a manner that, when in its relaxed state, the limbs 82 of the spring extend at different angles from the loop 84 which, in turn, means that the two spigots 82 are offset relative to each other. Because, by contrast, the apertures 88 in the upper body lie in register with each other, when the spigots 86 are located in the apertures 88, the tendency of the wire spring to seek to adopt its relaxed configuration therefore has the effect of biasing the loop 84 of the spring to rotate anti-clockwise (as viewed in FIG. 4) about the points of engagement of the spigots 86 with the apertures 88. This rotational biasing of the loop 84 causes it to bear against the slot 67 in the prong and bias the pawl 62 to pivot and thereby project further through the aperture 70. Conversely, the engagement of the loop 84 against the slot 67 defines what is effectively a rest position for the spring 80, when no external forces act on it.

In addition to biasing the prong of the locking member into the aperture 70, the wire loop spring 80 performs the further function of retaining the pull tab 100 in engagement within the jaws 50. Referring additionally to FIGS. 5 and 6, the pull tab 100 has a window section 110 at one end which terminates in a substantially cylindrical bar 112. To connect the pull tab 100 to the slider the bar 112 of the window section 110 is inserted between the jaws 50. As it is inserted, the bar 112 first comes into contact with the limbs 82 of the loop spring, the surfaces of which are angled relative to the vertical as a result firstly of the rotational biasing action of the loop spring 80 and secondly engagement of the loop 84 in the slot 67 which therefore prevents further rotation of the limbs 82 and loop 84. Further force applied to the pull tab 100 after it has come into contact with the limbs 82 of the wire spring 80 will act to cause the limbs 82 and loop 84 of the spring 80 to pivot in a clockwise direction (as viewed in FIG. 4) and thereby continue to permit insertion of the bar 112 into the jaws. This pivoting of the limbs 82 and loop 84 will continue until the bar 112 is inserted to a point where it passes beyond the loop 84, whereupon the bar 112 will no longer bear against either the limbs 82 or the loop 84 of the wire spring 80 and so the biasing action of the spring 80 will cause it to return to its rest position bearing against the slot 67. However, because the bar 112 now lies within the jaws and has passed beyond the wire spring 80, when the spring is in its rest position, the limbs 82 of the wire spring now operate to prevent the bar 112 from being removed from the jaws 50, since motion of the bar 112 in the reverse direction will merely urge the limbs 82 to push the loop 84 more forcefully into engagement with the slot 67. Since the locking member 60 has only a limited capacity for movement in the reverse direction before it comes into contact with an abutting surface 74 on the upper plate 14, motion of the limbs 82 in the anti-clockwise direction is therefore limited, with the result that the limbs 82 therefore act to retain the pull tab 100 in engagement with the body 10 of the slider.

The pull tab 100 is therefore now securely retained in the jaws 50 so that pulling forces applied to the pull tab 100 by a user will cause the entire body 10 of the slider to move relative to the zip teeth and, thereby fasten or unfasten the zip. It will be noted that the locking member 60 further comprises a recess 68. A fastening force, applied in the direction of arrow F, will cause the bar to bear against the groin 68A of the recess and this will have the effect, to some extent, of counteracting the biasing force applied by the wire spring 80 urging the pawl 62 into engagement with the zip teeth thereby enabling easier motion of the zip slider to fasten the zip. Conversely, an unfastening force applied by the pull tab 100 will initially cause the bar 112 to bear against the limbs 82 which will, in turn, urge the pawl 62 to bear more forcefully against the zip teeth and thereby act to prevent motion of the slider body 10 to unfasten the zip. However, as the unfastening force applied to the pull tab 100 increases, the bar 112 will be urged upwards by the angle of the limbs 82, and will then engage the upper limb 69 of the locking member. This will then have the effect of causing the prong 62 to lift away from the teeth so that further force applied by the pull tab 100, via the bar 112 will then unfasten the zip.

Removal of the pull tab may be undertaken, if desired, by inserting a suitable tool into the jaws 50 to displace the limbs 82 in a clockwise direction to a sufficient extent that the bar 112 may then pass back beyond the loop 84. This is a preferred method since it then enables easy re-insertion. Alternatively, the spigots of the wire spring.

In a modification of the embodiments described above, the zip slider is a non-locking zip slider and, accordingly, there is no mechanism to lock the zip teeth in place relative to the slider body. One embodiment of such a modification would simply be for the locking member 60 not to incorporate a prong 62 that projects onto the zip teeth. Another embodiment would be for the upper plate of the body to be formed such that a suitable slot is formed within it, having a similar shape to that of the slot 67 in the locking member.

Further, alternative embodiments of the present invention will now be described which include alternative spring configurations whereby no forces applied during movement of the slider can be applied to the locking prong.

Referring now to FIGS. 7 to 10, a slider comprises a body 200 having a base part 112 made of two mutually opposing upper and lower plates 114, 116 which, in conjunction with side walls 122, depending downwardly from the edges of the upper plate 114, are formed to create two angled entry channels which open onto the end 118 of the slider and into which the zip teeth (not shown) of the two opposing parts of an unfastened zip (not shown) are fed. The entry channels feed into a single mating channel which opens onto end 120. As the slider is moved along the zip in the direction of arrow F, the forces applied to the zip teeth by the side walls 122 urge the teeth to interdigitate and knit together, fastening the zip; the fastened zip exiting the slider via the mating channel at end 120. Movement of the slider relative to the zip teeth is actuated by means of a pull tab not shown.

To provide for connection of a pull tab to the slider body 200, the slider has an upper body 140 (sometimes referred to as a ‘bridge’) mounted on the base of the slider which, in conjunction with the upper surface of the upper plate 114 of the base forms a pair of jaws into which a window section of the pull tab may be inserted and by means of which the pull tab may be retained on the slider. In the design of the present embodiment enables the upper body 140 to be cast solidly with the other elements of the slider body, unlike existing locking sliders which are formed from several pieces.

Typically, a zip slider will include a mechanism which operates to lock the position of the slider relative to the zip teeth. Usually, this is a prong located on the zip slider and which projects into the mating channel to bear against the upper surface of the interdigitated zip teeth and, by virtue of that engagement, prohibit the relative motion of the slider and teeth. Evidently, any locking prong is desirably disengagable from the zip teeth in order to facilitate relative motion of the slider and zip teeth. In the present embodiment a locking prong 160 is provided at one end of an elongate, folded leaf spring 162. The leaf spring is folded in such a manner as to create two functional elements: a locking element 164 which is configured in a G shaped configuration with the locking prong 160 as the downward facing tail of the G; and a C shaped biasing element 166 from the lower part of which the locking element 164 depends. In use, the biasing element 166 urges the locking prong 160 of the locking element 164 downwardly and into engagement with the interdigitated zip teeth. The leaf spring 162 is retained on the upper body 140 by means of an end cap 142 which can be clipped into place after insertion of the leaf spring 162.

As with the previous embodiment, a pull tab (not shown) is retained within the jaws by means of a wire loop spring 180. The loop spring has two limbs 182 which extend from a loop 184 at its base 186. The loop spring 180 further has two spigots 188 which project outwardly from the upper ends of the limbs 182 and which extend into apertures 190 in the upper body 140 thereby to locate the spring in the upper body 114 in a manner permitting pivotal motion of the loop 184 at its lower extent relative to the upper body 114. The spring 180 is formed in such a manner that, when in its relaxed state, the limbs 182 of the spring extend at different angles from the loop 184 which, in turn, means that the two spigots 188 are offset relative to each other. Because, by contrast, the apertures 190 in the upper body 114 are positioned such that, when the spigots 186 are located in the apertures 190 the limbs 182 lie in register with each other or, in other words, are mutually aligned, the tendency of the wire spring 180 to seek to adopt its most relaxed configuration therefore has the effect of biasing the loop 184 of the spring 180 to rotate clockwise (as viewed in FIG. 13; anti clockwise in FIGS. 8 and 9) about the points of engagement of the spigots 188 with the apertures 190. This rotational biasing of the loop 184 causes it to bear against an abutting surface 200 (seen in FIG. 13) on the body of the slider. Connection of a pull tab therefore involves inserting the end of the pull tab between the jaws formed by the bridge 140 and upper surface of the body 114. This motion causes the pull tab to bear against the limbs 182 of the loop spring 180, the facing surfaces of which are angled relative to the vertical as a result firstly of the rotational biasing action of the loop spring 180 and secondly engagement of the loop 184 with the surface 200 and, against the natural biasing action of the spring 180 arising as a result of the offset limbs 182, causes them and the loop 184 to rotate anti-clockwise in FIG. 13 (clockwise in FIGS. 2 and 3). Continuing force applied to the pull will cause the limbs 182 and loop 184 of the spring 180 to pivot until the bar of the pull tab is inserted to a point where it passes beyond the loop 184. Once the bar of the pull tab is clear of the loop 184, the biasing action of the spring 180 will cause the limbs 182 and loop 184 to snap back into abutment with the surface 200. Because the bar of the pull tab now lies within the jaws and has passed beyond the wire spring 180, when the spring is in its rest position, motion of the bar in the reverse direction will merely urge the limbs 182 to push the loop 184 more forcefully into engagement with the surface 200 with the result that the limbs 182 of the loop spring 180 now operate to prevent the pull tab from being removed from the jaws.

In order to move relative to the zip teeth, the locking prong 160 must be disengaged from the zip teeth. This occurs as a result of the pulling action of the pull tab during unzipping. The action which is to be described can more readily be appreciated when viewing the section of FIG. 10. Pulling of the pull tab perfectly horizontally against the loop spring causes it first to bear against the angled limbs 182 of the locking spring 180 whereupon it will ride up the angled surfaces of the limbs 182 and bear upwardly against the upper surface of the locking element 164. That upward force acts against the downward biasing action of the biasing element 166 to cause upward, disengaging motion of the locking element 164 thereby bringing the locking prong 160 out of engagement with the interdigitated zip teeth (not shown) which, in turn then permits movement of the zip slider body. In practice, because users almost always pull a zip slider from a point somewhat outwardly displaced from the zip, almost all forces applied by the pull tab on the slider body will additionally involve some upward component. When the zip slider is pull with such an additional upward component, the result is a yet greater disengaging force applied to the locking element 164 and against the action of the biasing element 166.

A feature of the present embodiment is that the loop 184 of the spring 180 bears against an abutting surface 200 on the slider body and therefore no forces applied to the loop spring can cause any increase in force applied to the locking prong.

Referring now to FIGS. 11 and 12, a modification of the embodiment of FIGS. 7 to 10 is now illustrated. In addition, the angle of illustration of this modification enables the mating channel indicated by reference numeral 120M to be more clearly seen as well as one of the entry channels 118E a modification, the locking element 164 and biasing element 166 are two separate structures. The locking element 164 is formed as a relatively rigid monolithic metal structure (typically die cast from aluminium) and the biasing element is a leaf spring 166 which bears against a hook 168 in the rear of the locking element 164 and downwardly against a shoulder 169 in the upper surface of the locking element 164 to urge the locking prong 160 into engagement with the interdigitated teeth. Disengagement of the locking prong 160 occurs in precisely the same way as a result of the same mechanism as described previously in connection with FIGS. 7 to 10.

Referring now to FIG. 13, in yet a further modification, a zip slider is provided without any locking capability. The zip slider of this embodiment therefore merely includes the loop spring 180 to retain the pull tab.

In each of the foregoing embodiments, removal of the pull tab may be undertaken, if desired, by inserting a suitable tool into the jaws to displace the limbs 182 to a sufficient extent that the bar of the pull tab may then pass back beyond the loop 184 whereupon the pull tab may be removed. This is a preferred method since it then enables easy re-insertion.

The embodiments of the present invention described above therefore provide the ability to latch a pull tab onto the slider yet with a simple and low-cost construction. The ability to attach a pull tab to a slider in this way is advantageous for a number of reasons. It enables manufacturers to use different designs of pull tab in dependence upon the style of garment in which the zip is to be used, without having to purchase different zips in order to do so. Further, it permits the entire construction of the garment, including stitching and dyeing to be completed before attaching the pull tab, thereby minimising the risk of damage to the garment or zip slider as a result of the need to subject the zip with a pull tab attached to the rigours of those processes.

The various modifications to embodiments disclosed herein are not limited in their applicability to the embodiment in connection with which they were first described and, unless specifically stated otherwise, any modification is equally applicable to all other embodiments described herein. 

1. A zip slider comprising: a body having two channels through which opposing rows of zip teeth may be respectively fed into a single channel in which the zip teeth are forced into interdigitation; upper and lower jaw members mounted on the body and defining a slot between them; a biasing member, pivotally mounted on the body, and being pivotable in a first direction between a rest position and a deflected position, wherein pivoting of the biasing member out of the rest position permits insertion of a loop of a pull tab into to the jaws and, in the rest position, the biasing member prohibits removal of the pull tab from the jaws.
 2. A zip slider according to claim 1 wherein the biasing member is a wire spring, pivotally mounted upon one of the jaw members.
 3. A zip slider according to claim 2 wherein the wire spring is formed as a loop having a pair of limbs whose ends are pivotally engaged with the one of the jaw members.
 4. A zip slider according to claim 3 wherein the wire of the loop is formed with its limbs mutually offset thereby to provide pivotal biasing action of the loop relative the body when the limbs are brought into register with each other.
 5. A zip slider according to claim 2 wherein each limb comprises a spigot at its end and the biasing member is mounted on the body by engagement of the spigots in apertures within the body.
 6. A zip slider according to claim 2 wherein the limbs are of equal length.
 7. A zip slider according to claim 2 wherein the limbs are of differing lengths.
 8. A zip slider according to claim 1 wherein, in the rest position, the biasing member bears against the body.
 9. A zip slider according to claim 1 further comprising a locking member, mounted to the body and having a prong which may retractably project through an aperture in the body and thereby engage the inter-digitated zip teeth.
 10. A zip slider according to claim 9 wherein the biasing member bears against the locking member thereby to bias the prong into engagement with the zip teeth.
 11. A zip slider according to claim 9 wherein the locking member is pivotally mounted on the body and pivoting of the locking member enables projection of the prong into and retraction of the prong from the aperture.
 12. A zip slider according to claim 10 wherein the biasing member is a wire spring, pivotally mounted on one of the jaw members and bearing against the locking member at a point of the wire spring remote from the pivot.
 13. A zip slider according to claim 1 wherein the biasing member is pivotally mounted on the upper jaw member.
 14. A zip slider according to any one of claim 9 wherein the locking member is pivotally mounted on the lower jaw member.
 15. A zip slider according to claim 1 wherein zip teeth pass through the channel in a first direction, thereby to define a vertical axis orthogonal to the first direction, and the biasing member has a surface which is deflectable upon pivoting from the rest position to increase the angle of the surface relative to the vertical.
 16. A zip slider according to claim 10 wherein the loop bears against the locking member. 